The director of rugby told Sky Sports News: "It's only damaging if you let it be damaging. People think sport is about this upward curve and you never get blips or disappointments, but without this the emotion of the wins would never be as high.
"You have to take it and actually how you react to adversity is actually more important than being able to take the good times the whole time.
"Northampton, on the balance of it, deserve to win [last night] I think, we didn't bring everything we're about. But, we keep putting ourselves in these positions, sometimes you have disappointment and sometimes you have success."
Harlequins play Exeter Chiefs next weekend.